The present invention relates to seatbelt systems and, more particularly, to a pretensioner for a seatbelt system.
Seatbelt pretensioners remove slack from a safety belt in the event of a collision in order to minimize forward movement of the passenger. Many existing pretensioner designs are used in conjunction with a conventional seatbelt retractor, and utilize a clutch assembly for coupling the pretensioner to the retractor in the event of a collision, to enable pretensioning of the seatbelt. However, such clutch assemblies add to the expense and complexity of the seatbelt system. Clutch assemblies also add to the space occupied by the seatbelt system.
The present invention provides advantages over known pretensioner designs, which typically utilize a pretensioning mechanism situated outside of the retractor frame. By locating the pretensioning mechanism inside the retractor spool, the size of the pretensioner/retractor assembly can be reduced compared to known designs. In addition, in the design disclosed herein, a clutch assembly is not required to couple the pretensioner and the retractor spool.